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RenderSliverFixedExtentBoxAdaptor

inset_rendering

Trait RenderSliverFixedExtentBoxAdaptor 

Source 
pub trait RenderSliverFixedExtentBoxAdaptor: RenderSliverMultiBoxAdaptor {

Show 14 methods    // Required methods
    fn fixed_extent_data(
        self: RenderHandle<Self>,
        app: &App,
    ) -> &RenderSliverFixedExtentBoxAdaptorData;
    fn fixed_extent_data_mut(
        self: RenderHandle<Self>,
        app: &mut App,
    ) -> &mut RenderSliverFixedExtentBoxAdaptorData;
    fn item_extent(self: RenderHandle<Self>, app: &App) -> Option<f64>;

    // Provided methods
    fn item_extent_builder(
        self: RenderHandle<Self>,
        app: &App,
    ) -> Option<ItemExtentBuilder> { ... }
    fn layout_dimensions(
        self: RenderHandle<Self>,
        app: &App,
    ) -> SliverLayoutDimensions { ... }
    fn index_to_layout_offset(
        self: RenderHandle<Self>,
        app: &App,
        index: i32,
    ) -> f64 { ... }
    fn get_min_child_index_for_scroll_offset(
        self: RenderHandle<Self>,
        app: &App,
        scroll_offset: f64,
    ) -> i32 { ... }
    fn get_max_child_index_for_scroll_offset(
        self: RenderHandle<Self>,
        app: &App,
        scroll_offset: f64,
    ) -> i32 { ... }
    fn child_index_for_scroll_offset(
        self: RenderHandle<Self>,
        app: &App,
        scroll_offset: f64,
        builder: &ItemExtentBuilder,
    ) -> i32 { ... }
    fn estimate_max_scroll_offset(
        self: RenderHandle<Self>,
        app: &App,
        constraints: SliverConstraints,
        first_index: Option<i32>,
        last_index: Option<i32>,
        leading_scroll_offset: Option<f64>,
        trailing_scroll_offset: Option<f64>,
    ) -> f64 { ... }
    fn compute_max_scroll_offset(
        self: RenderHandle<Self>,
        app: &mut App,
        _constraints: SliverConstraints,
    ) -> f64 { ... }
    fn child_constraints(
        self: RenderHandle<Self>,
        app: &App,
        index: i32,
    ) -> BoxConstraints { ... }
    fn paint_extent_of(
        self: RenderHandle<Self>,
        app: &App,
        child: AnyRenderBox,
    ) -> f64 { ... }
    fn perform_layout(self: RenderHandle<Self>, app: &mut App) { ... }

}
Expand description

A sliver that contains multiple box children that have the same extent in the main axis.

Flutter’s RenderSliverFixedExtentBoxAdaptor. An implementor answers either item_extent or item_extent_builder.

Required Methods§

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fn fixed_extent_data( self: RenderHandle<Self>, app: &App, ) -> &RenderSliverFixedExtentBoxAdaptorData

Mixin field access.

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fn fixed_extent_data_mut( self: RenderHandle<Self>, app: &mut App, ) -> &mut RenderSliverFixedExtentBoxAdaptorData

See fixed_extent_data.

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fn item_extent(self: RenderHandle<Self>, app: &App) -> Option<f64>

The main-axis extent of each item.

If this is Some, item_extent_builder must be None. If this is None, item_extent_builder must be Some.

Provided Methods§

Source

fn item_extent_builder( self: RenderHandle<Self>, app: &App, ) -> Option<ItemExtentBuilder>

The main-axis extent builder of each item.

If this is Some, item_extent must be None. If this is None, item_extent must be Some.

Source

fn layout_dimensions( self: RenderHandle<Self>, app: &App, ) -> SliverLayoutDimensions

The layout dimensions for the sliver.

If the sliver has not been laid out yet, this returns a SliverLayoutDimensions based on the current constraints.

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fn index_to_layout_offset( self: RenderHandle<Self>, app: &App, index: i32, ) -> f64

The layout offset for the child with the given index.

This function uses the returned value of item_extent_builder or the item_extent to avoid recomputing item size repeatedly during layout.

By default, places the children in order, without gaps, starting from layout offset zero.

Source

fn get_min_child_index_for_scroll_offset( self: RenderHandle<Self>, app: &App, scroll_offset: f64, ) -> i32

The minimum child index that is visible at the given scroll offset.

By default, returns a value consistent with the children being placed in order, without gaps, starting from layout offset zero.

Source

fn get_max_child_index_for_scroll_offset( self: RenderHandle<Self>, app: &App, scroll_offset: f64, ) -> i32

The maximum child index that is visible at the given scroll offset.

By default, returns a value consistent with the children being placed in order, without gaps, starting from layout offset zero.

Source

fn child_index_for_scroll_offset( self: RenderHandle<Self>, app: &App, scroll_offset: f64, builder: &ItemExtentBuilder, ) -> i32

Flutter’s _getChildIndexForScrollOffset.

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fn estimate_max_scroll_offset( self: RenderHandle<Self>, app: &App, constraints: SliverConstraints, first_index: Option<i32>, last_index: Option<i32>, leading_scroll_offset: Option<f64>, trailing_scroll_offset: Option<f64>, ) -> f64

Called to estimate the total scrollable extents of this object.

Must return the total distance from the start of the child with the earliest possible index to the end of the child with the last possible index.

By default, defers to RenderSliverBoxChildManager::estimate_max_scroll_offset.

Source

fn compute_max_scroll_offset( self: RenderHandle<Self>, app: &mut App, _constraints: SliverConstraints, ) -> f64

Called to obtain a precise measure of the total scrollable extents of this object.

This is used when no child is available for the index corresponding to the current scroll offset, to determine the precise dimensions of the sliver.

If item_extent_builder is None, multiplies the item_extent by the number of children reported by RenderSliverBoxChildManager::child_count. Otherwise, sums the extents of the first child_count children.

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fn child_constraints( self: RenderHandle<Self>, app: &App, index: i32, ) -> BoxConstraints

Flutter’s _getChildConstraints.

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fn paint_extent_of( self: RenderHandle<Self>, app: &App, child: AnyRenderBox, ) -> f64

The body of Flutter’s paintExtentOf override.

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fn perform_layout(self: RenderHandle<Self>, app: &mut App)

The body of Flutter’s performLayout override.

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§